This invention relates to a wobble engine including a housing and a wobble plate assembly that wobbles within the housing to rotate a shaft of the engine.
U.S. Pat. No. 4,688,522 McMaster and U.S. Pat. No. 4,799,870 McMaster disclose fluid power transfer devices wherein a generally spherical housing receives rotors that have conical faces which roll against each other in association with a vane to provide a rotary output to shafts connected to the rotors.
Also, U.S. Pat. No. 5,251,594 Meyer discloses a neutating internal combustion engine wherein a crankshaft has an angular portion that connects two drive shafts and is received within a ball having an annular disk with conical faces that roll along opposing parallel wall surfaces. Fuel supplied within the engine through associated valves provides a rotary motion to the crankshaft and driving of its shafts connected by the angular shaft portion. Precise and hence relatively expensive machining of the crankshaft is required so that the ball and its annular disk with the conical surfaces will roll against the engine wall surfaces and rotate the crankshaft through its angular portion.
An object of the present invention is to provide an improved wobble engine for use as an internal combustion engine, a heat engine, or a fluid power transfer device for transferring power to or from rotary motion.
In carrying out the above object, the wobble engine of the invention has a housing including an outer annular portion having an interior with a spherical shape that is symmetrically truncated on opposite sides of a great circle of its spherical shape. The housing also includes a pair of cone portions that converge toward each other along a central rotational axis and that have truncated inner extremities. The spherically shaped outer annular portion cooperates with the truncated cone portions to define an annular cavity. A vane extends parallel to the central axis across the annular cavity. A shaft of the engine extends along and is rotatable about the central axis. The engine also includes a wobble plate assembly located within the housing for wobbling motion and including a spherical member rotatively fixed to the shaft. The spherical member has an annular bearing that extends obliquely with respect to the central axis. The wobble plate assembly also includes a wobble plate of a generally annular shape having an inner extremity that is rotatably supported by the annular bearing of the spherical member and having an outer extremity that is slidably engaged with the spherical shape of the outer annular portion of the housing. The wobble plate has a slot that extends radially with respect to the spherical member and that receives the vane of the housing in a slidable relationship with the vane. The wobble plate has oppositely facing surfaces that respectively roll along the pair of truncated cone portions of the housing at diametrically opposite sides of the spherical member.
The wobble engine as disclosed includes a pair of combustion chambers spaced form each other along the central axis on one circumferential side of the vane. The housing also includes a pair of exhaust chambers spaced from each other along the central axis on the opposite circumferential side of the vane as the pair of combustion chambers. Each of the pair of combustion chambers includes an associated fuel injector for injecting fuel thereinto for combustion, and each of the pair of combustion chambers also includes a glow plug for igniting the fuel for combustion. The wobble engine has particular utility for use with two component fuels such as hydrogen and oxygen, propane and oxygen, and ammonia and nitrous oxide. Each of the pair of combustion chambers includes an associated fuel injector for receiving the two fuel components for injection into the combustion chamber where each combustion chamber has a glow plug for igniting the ammonia and nitrous oxide for combustion. The combustion chambers also are disclosed as having a refractory liner that is preferably made of silicon carbide, a refractory oxide or a mixture of refractory oxides.
The wobble plate of the wobble engine includes a vane seal that defines the slot thereof for slidably sealing with the vane. The wobble plate has a radially extending round bore and radially extending openings through which the vane extends, and the vane seal is constructed as a bifurcated dowel having seal portions that slidably contact opposite sides of the vane.
The wobble engine is also disclosed in one embodiment as including a second vane that extends parallel to the central axis across the annular cavity. The wobble plate has a second slot that extends radially with respect to the spherical member and that receives the second vane of the housing in a slidable relationship therewith. The wobble plate of this embodiment includes a pair of vane seals that define the slots thereof for slidably sealing with the vanes. The wobble plate in this embodiment has a pair of radially extending round bores and radially extending openings through which the vanes extends and each vane seal is embodied by a bifurcated dowel having seal portions that slidably contact opposite sides of the vane.
One embodiment of the wobble engine includes an oil lubrication and cooling system for passing oil into the housing, through the wobble plate assembly, and back out of the housing. This oil lubrication and cooling system includes an oil inlet into the housing, supply passages in the housing from the inlet to the wobble plate assembly, distribution passages in the wobble plate assembly for distributing the oil to the inner and outer extremities of the wobble plate, return passages in the housing from the wobble plate assembly, and an oil outlet to which the return passages return the oil from the wobble plate assembly for flow out of the housing for cooling and recycling. The wobble plate includes a first set of radially extending distribution passages that are spaced circumferentially from each other and having inner and outer ends with the inner ends being fed oil from the supply passages adjacent the inner extremity of the wobble plate. An annular outer distribution passage of the wobble plate receives oil from the outer ends of the first set of radially extending distribution passages. A second set of radially extending distribution passages of the wobble plate are spaced circumferentially from each other and have inner and outer ends with the outer ends receiving oil from the annular outer distribution passage and with the inner ends feeding the oil to the return passages for flow from the housing through the oil outlet. The first and second sets of radially extending distribution passages of the wobble plate are circumferentially spaced in an alternating relationship with respect to each other for uniform cooling.
The outer extremity of the wobble plate includes an outer annular central seal that slidably seals with the spherically shaped outer annular portion of the housing. The outer extremity of the wobble plate also has oil seal passages that extend from the annular distribution passage to the outer annular central seal to provide lubrication. The wobble plate also includes a pair of outer annular side seals located on opposite sides of the outer annular central seal, and the outer extremity of the wobble plate has side seal passages that extend from the annular cavity to the outer annular side seals such that pressure supplied thereto from the annular cavity provides sealing thereof with the spherically shaped outer annular portion of the housing.
In its preferred construction, the wobble plate includes a central plate and an outer annular ring that cooperates with the central plate to define the annular outer distribution passage. The outer annular ring has an annular central groove that receives the outer annular central seal and has a pair of annular side grooves that respectively receive the pair of outer annular side seals. The outer annular ring defines the oil seal passages and the side seal passages.
The shaft of the wobble engine includes a first helical groove for preventing the oil from exiting the supply passages adjacent the shaft. The shaft also includes a second helical groove for preventing the oil from exiting the return passages adjacent the shaft.
Different embodiments of the annular bearing are disclosed. In one embodiment, the annular bearing is a journal bearing including an annular groove in the spherical member that receives and rotatably supports the inner extremity of the wobble plate. In another embodiment, the annular bearing is an antifriction thrust bearing including roller elements. In a further embodiment, the annular bearing includes at least one antifriction roller bearing that rotatably supports the inner extremity of the wobble plate on the spherical member and has roller elements that rotate about associated axes extending transverse to the wobble plate.
The housing of the wobble engine includes a generally annular housing member having opposite axial ends and an intermediate portion that extends between its ends and defines the spherically shaped outer annular portion of the housing. The housing also includes a pair of cone members that are respectively secured to the opposite axial ends of the annular housing member and have frustoconical surfaces that define the truncated cone portions of the housing. The frustoconical surfaces of the cone members have plate seals that extend radially and axially from the central axis and that seal with the wobble plate upon rolling thereof along the frustoconical surfaces. The frustoconical surfaces of the cone members have seal grooves, while the plate seals include seal members that are respectively received by the seal grooves with springs of the plate seals resiliently biasing the seal members. The seal members have outer extremities that are resiliently positioned outwardly from the seal grooves so as to resiliently engage and seal with the wobble plate upon the rolling thereof along the frustoconical surfaces.
The annular housing member and the pair of cone members have vane grooves that receive the vane that extends across the annular cavity of the housing. The vane has a partially circular inner extremity that slidably contacts the spherical member of the wobble plate assembly. The vane groove of the annular housing member includes a spring that resiliently biases the vane against the spherical member of the wobble plate assembly to accommodate for thermal expansion and contraction.
The housing of the wobble engine includes a pair of annular end plates secured to the annular housing member, and the pair of cone members have support portions that are respectively supported by the pair of annular end plates. The support portions of the cone member have the shaft extending therethrough and include seals that rotatably seal with the shaft and with the spherical member of the wobble plate.
The disclosed construction of the annular housing member includes half sections that have semicircular shapes with engaged faces that are secured to each other.
The spherical member of the wobble plate includes a pair of hemispheres having engaged faces that each include an annular groove portion for cooperating with the other annular groove portion to define the annular groove of the spherical member.
The one embodiment of the annular bearing discussed above includes a pair of antifriction roller bearings that rotatably support the inner extremity of the wobble plate on the spherical member and have roller elements that rotate about associated axes extending transverse to the wobble plate. This embodiment of the wobble engine also includes a pair of antifriction roller bearings that rotatably support the shaft on the housing. Furthermore, this embodiment of the wobble engine includes a pair of seals that rotatively seal between the shaft and the housing outward from the pair of antifriction roller bearings that rotatably support the shaft on the housing.
The objects, features and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.